Write an equation for the parabola.
-vertex $( - 9,7 )$, focus $( - 20,7 )$
A) $( y - 7 ) ^ { 2 } = - 44 ( x + 9 )$
B) $x + 9 = - 44 ( y - 7 ) ^ { 2 }$
C) $x + 7 = - 20 ( y - 9 ) ^ { 2 }$
D) $- 44 ( x - 9 ) = ( y + 7 ) ^ { 2 }$

Question

Quizplus · Accepted Answer

The correct equation for a parabola with a horizontal axis is $(y-k)^2=4p(x-h)$, where $(h,k)$ is the vertex and $p$ is the distance from the vertex to the focus. Here, the vertex is $(-9,7)$ and the focus is $(-20,7)$, so $p = -11$ (since the focus is to the left of the vertex). Substituting $h = -9$, $k = 7$, and $p = -11$ into the formula gives $(y-7)^2 = -44(x+9)$.

Write an Equation for the Parabola (−9,7)( - 9,7 )(−9,7) , Focus

Write an Equation for the Parabola $( - 9,7 )$ , Focus